Zhao Fengchao, Li Zirong, Zhang Nianfei, Shi Zhencai, Zhang Xuezhe
Center for Osteonecrosis and Joint-Preserving & Reconstruction, China-Japan Friendship Hospital, Beijing, 100029, P. R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2005 Sep;19(9):687-91.
To explore the program for calculating the necrotic articular surface area (NASA) and the ratio of NASA to whole articular surface area (WASA) of osteonecrosis of the femoral head (ONFH), to verify the accuracy of this calculation and to predict the collapse of the femoral head clinically using this program.
From June 2001 to June 2003, The specimens of the necrotic femoral head from eight patients (13 hips) were obtained by total hip arthroplasty. The magnetic resonance imaging (MRI) was taken in all patients before operation. According to a series of T1-weight pictures, the NASA and the ratio of NASA to WASA were calculated by designing program. The specimens of the necrotic femoral head were sawed into lays similar to MRI pictures using the coordinate paper stick on the auricular surface, the data processing were done by analytic instrument for pictures. The data of both were analyzed statistically by software SPSS 10.0 edition. The NASA and the ratio of NASA to WASA were calculated on MRI in ARCO Stage I, II 16 patients (25 hips) with non-operation. Follow-up was done to the patients with collapse of the femoral head and to the patients with no collapse for at least 24 months. The data were compared in collapse group and non-collapse group.
There were no significant differences between MRI pictures calculation and specimens measurement (NASA: 0. 412, ratio of NASA to WASA: 0.812, P>0.05). Of the 25 hips followed up, collapse occurred in 17 hips. NASA was 31.06+/-8.10 cm2, (95% CI. 26.58 to 35.55), the ratio of NASA to WASA was 58.91%+/-15.11%, (95% CI: 51.14 to 66. 68). No collapse appeared in 8 hips. NASA was 14.16+/-9.32 cm2 (95% CI: 6.04 to 21. 95), the ratio of NASA to WASA was 29.48%+/-19.76% (95% CI: 12.97 to 45.99). The ratio in the patients with collapse was beyond 33%.
The NASA and the ratio of NASA to WASA in patients with ONFH can be accurately calculated with the MRI pictures. The possibility of collapse can be predicted by this method. As it is complicated in operation, improvement should be made in order to put it into clinical use.
探索计算股骨头坏死（ONFH）坏死关节表面积（NASA）及其与整个关节表面积（WASA）比值的程序，验证该计算的准确性，并利用此程序临床预测股骨头塌陷。
2001年6月至2003年6月，通过全髋关节置换术获取8例患者（13髋）坏死股骨头标本。所有患者术前均行磁共振成像（MRI）检查。根据一系列T1加权图像，通过设计程序计算NASA及其与WASA的比值。将坏死股骨头标本贴附坐标纸后锯成与MRI图像相似的层面，利用图像分析仪进行数据处理。采用SPSS 10.0版软件对两者数据进行统计学分析。对16例（25髋）ARCO I、II期非手术治疗的患者行MRI检查计算NASA及其与WASA的比值。对出现股骨头塌陷的患者和未出现塌陷的患者进行至少24个月的随访。比较塌陷组和未塌陷组的数据。
MRI图像计算结果与标本测量结果无显著差异（NASA：0.412，NASA与WASA比值：0.812，P>0.05）。随访的25髋中，17髋出现塌陷。NASA为31.06±8.10 cm²（95%CI：26.58至35.55），NASA与WASA比值为58.91%±15.11%（95%CI：51.14至66.68）。8髋未出现塌陷。NASA为14.16±9.32 cm²（95%CI：6.04至21.95），NASA与WASA比值为29.48%±19.76%（95%CI：12.97至45.99）。塌陷患者的比值超过33%。
利用MRI图像可准确计算ONFH患者的NASA及其与WASA的比值。该方法可预测塌陷可能性。由于操作复杂，应加以改进以便临床应用。
